Prader-Willi Syndrome (PWS) Information for parents and carers

Transcription

1 Prader-Willi Syndrome (PWS) Information for parents and carers

2 Who this booklet is intended for This booklet is intended for parents and carers of children with PraderWilli Syndrome (PWS). The purpose of this booklet is to provide some basic information about PWS and the role that growth hormone treatment can play in helping your child. This booklet should help to explain the benefits of growth hormone treatment, address any concerns or fears you may have, and provide information about where to go for further information and support. Genotropin PWS Gen 2929 v3.indd 2 30/4/09 13:28:15

3 Introduction Prader-Willi Syndrome is a rare condition identified by characteristic clinical signs and symptoms, and confirmed by genetic tests. Like many genetic conditions, there is no cure; however there are many ways in which you and your doctor can help your child. All children with PWS have a problem in a key area of their brain, the hypothalamus, which controls their growth, energy levels, hunger and sleep. Perhaps one of the most difficult features of PWS that your child may experience is the uncontrollable urge to eat. Children with PWS will frequently have reduced levels of growth hormone, which can lead to short stature and an imbalance in body composition leading your child to have more fatty tissue and less muscle than usual. Short stature and body composition respond particularly well to treatment with growth hormone therapy. This booklet will explain how treatment with growth hormone can help your child to reach a more normal adult height, improve their ratio of muscle to fat, and help them achieve a better quality of life. Your paediatrician, geneticist or endocrinologist (doctors who specialise in hormone problems) are available to explain the challenges posed by PWS as your child grows up, and will be a major source of guidance and support to your family. Receiving a diagnosis that explains your child s condition may be reassuring, but it can also bring with it a whole host of new questions and concerns. While this booklet should answer many of your questions, your healthcare team are also there to provide you with support and advice. There are also many organisations and resources dedicated to providing help and support to parents and children with PWS. Contact details for organisations are listed at the end of this booklet. Additionally, your healthcare professional can provide you with details of local organisations and support groups for families affected by PWS.

4 Growing up with Prader-Willi Syndrome Causes of Prader-Willi Syndrome PWS is caused by an abnormality on chromosome 15, where certain genes are absent or faulty. Both sexes and all races can be affected. This is a random and rare event, which could not have been predicted, and is highly unlikely to occur in future pregnancies. The fact that a child has PWS has nothing to do with the things the parents may or may not have done before or during the pregnancy.

5 Characteristics of Prader-Willi Syndrome PWS is often picked up soon after birth, when a baby shows signs of severe muscle weakness, poor feeding and slow growth. They may often have to be tube-fed for the first few days or weeks of life. They are often described as floppy babies, showing little movement, and may be slow to sit up or walk. Their muscle weakness means they get tired faster than other babies and toddlers of the same age. The PWS baby s poor feeding habits undergo a dramatic change as they become a toddler, giving way to a characteristic impulse to over-eat, and a preoccupation with food. Children with PWS have an inability to feel full and in addition, their energy requirement is 30% lower than average. Children with PWS often show distinctive facial features, including a narrow face, almond-shaped eyes and smaller than average mouth. They may have reduced levels of pigmentation and have fairer hair and skin than their family. They are usually shorter than other children, with smaller hands and feet, and are physically inactive - often falling asleep during the day if they sit still. People with PWS have poor large muscle strength, often combined with a lack of coordination and balance. This can be improved with physical therapy and exercise. Children with PWS do not usually go through a normal puberty, and may have less well-developed genitalia and impaired sexual development. Puberty generally arrives late, if at all. Unless access to food is controlled, food foraging is common and obesity can become a problem. Managing your child s diet will be vital to reduce the likelihood of obesity, and protect your child from associated longterm health issues such as joint problems, diabetes, high blood pressure, scoliosis and breathing problems. Most children with PWS will also have some degree of learning or behavioural difficulties that will need added support. You can find support and advice from the organisations listed at the end of this booklet, or your healthcare professional can point you in the right direction.

6 Challenges and solutions Caring for a child with PWS may pose some unique challenges for you and your family. Learning as much as you can about PWS, how best to manage it, and making sure your child understands the condition, can help you to bring your child up to be healthy and happy and able to cope with the challenges that will face them as they grow older. Your healthcare team will monitor for medical problems, and advise on specific treatments and emotional support to suit your child s individual needs. Living with Prader-Willi Syndrome Early problems with poor muscle tone usually resolve with age, and most children will manage to walk unaided. Physiotherapy and occupational therapy are often beneficial to help improve strength, balance and coordination. Children with PWS start to develop an often insatiable appetite by the time they are about 4 years old. Management and supervision of their diet is essential to prevent obesity. Helping your child by educating them about their diet, and monitoring their energy intake can help maintain good dietary control and prevent weight gain. With their reduced energy requirement, over-eating can cause rapid weight gain in a person with PWS, so a low-calorie diet needs to be followed throughout their life. Your doctor and dietician can work with you to assess portion sizes and plan a healthy balanced diet. This should be coupled with a tailored exercise programme to help control weight and improve muscle strength. Children with PWS are usually placid and friendly but may exhibit obsessive or stubborn behaviour if they are denied access to food, do not get their own way, or are experiencing change or an unexpected situation. They may benefit most from a daily routine and a structured environment.

7 The role of growth hormone Grow Grow Grow Grow Pituitary gland Approximately 40% of children with PWS do not produce enough growth hormone, a vital hormone essential for normal childhood growth. What is growth hormone? Growth hormone is a substance produced naturally in the pituitary gland a small collection of cells at the base of the brain about the size of a pea. Growth hormone is a messenger which stimulates the growth of tissues throughout the body. Some of its effects are directly on growth while others are on other pathways also involved in the growth process. It plays an essential role in the regulation of normal childhood growth. Growth hormone also has other important effects on how the body functions, not just during childhood but throughout our lives. It affects how the body deals with carbohydrates, fats and proteins, and may also affect the amount of energy we have. Why your child may require growth hormone The pituitary gland, which produces growth hormone, is under the control of the hypothalamus, the part of the brain that does not function properly in a child with PWS. Normally growth hormone is released by the pituitary gland into the blood stream every day, with more being produced at night time. Approximately 40% of children with PWS are not able to produce enough growth hormone and, if left untreated, would be shorter than expected and will fail to go through their pubertal growth spurt. Even if your child produces enough, supplementing the natural production can help keep the balance of fat and muscle in your child s body more like that of a child without PWS.

8 How growth hormone treatment can help Supplementing the body s natural production of growth hormone with synthetic growth hormone, can help rectify certain features of PWS. It can help to correct impaired growth and improve body composition (the balance of fat and muscle in the body) in children with PWS. Growth hormone treatment involves administering a synthetic (man-made) version of growth hormone to your child. This synthetic hormone has been available since 1985 and has been extensively tested. It is manufactured to be identical in its structure and effects to natural growth hormone. Growth hormone is a protein, and as such cannot be administered in tablet form (it would be broken down by the gastric juice in the stomach before your child s body could benefit from it). Treatment is therefore by regular daily injection given in a way that mimics the body s own production of growth hormone. The growth hormone dosage is determined based on your child s height and weight. Genotropin PWS Gen 2929 v3.indd 8 30/4/09 13:28:26

9 What if I have trouble injecting my child? As a parent or carer you are never expected, nor do you need, to be a nurse. The commercially available growth hormone devices are very user-friendly, and you will be trained on their proper use by a healthcare professional. You will be able to easily and confidently administer the therapy to your child with minimal guidance. When your child is old enough, he or she will be able to administer it themselves. Naturally, you don t want to do anything that will cause your child pain or discomfort. It s not uncommon to be apprehensive about administering an injection to your child. It is important to bear in mind both the consequences of PWS and the benefits your child stands to gain through growth hormone therapy. How will growth hormone therapy fit into our lives? The good news is that taking growth hormone therapy is a relatively simple procedure. Your child will receive an injection of their proper dose, every evening, to mimic their body s natural production of growth hormone. At first, you will have to administer the injection, but as your child gets older, they may be able to take over and be responsible for their treatment. It won t take long before the therapy becomes as normal a part of the daily routine as brushing their teeth before bed. There are many different varieties of injection devices on the market, each with their own advantages. It will not be difficult to find the device that fits your lifestyle and allows easy incorporation into your daily routine.

10 What can my child expect from growth hormone therapy? Improvements in height Most children exhibit a period of catch-up growth soon after therapy is started. As the name suggests, it seems that the body enters a phase of compensatory growth to make up for lost time. This phase is usually seen in the first year on growth hormone treatment. After this, most children s growth will normalise, or fall into line, with the expected growth pattern for their sex and age. However, regular treatment is essential to ensure continual growth. If your child were to stop his or her treatment, growth would most likely slow again. Improvements in body shape Prader-Willi Syndrome is one of the medical conditions where replacement of growth hormone has been shown to offer significant effects on body shape, as well as height. Fat is reduced and muscle increases. This shift from fat mass to lean muscle mass may be quite visible in your child, and can be shown medically using scans that assess body composition. In addition, physical fitness improves during growth hormone treatment. Improvements in well-being Obesity can cause heart and circulation problems and puts extra pressure on bones and stress on the lungs. Improving the balance between fat and muscle is a positive step towards keeping your child healthy and happy. The risks of cardiovascular disease and diabetes in later life will also be greatly reduced. Parents have reported that children are more willing to exercise after taking growth hormone treatment. Sleep patterns may also be improved.

11 How long will my child need growth hormone therapy? As with initiating therapy, the decision of when to stop therapy is made on an individual basis by your child s doctor. They will determine a target height based on the height and growth patterns which run in your family. In theory growth hormone treatment should stop when final adult height is reached. This is the case when growth during the last year has been less than 2 centimetres. Are there side effects associated with growth hormone therapy? Side effects of growth hormone therapy are rare, and your child will be continuously monitored by their medical team.

12 How do we grow? Growth Stages A child s growth can be broadly defined as falling into three stages: 1 Infancy 2 Childhood 3 Adolescence Infancy Childhood Adolescence The first period Infancy represents the first two years of life. During this period, the majority of children experience their most rapid growth. This growth is believed to be largely influenced by nutrition. The second phase Childhood is from age 2 to just before puberty. During these years growth slows down, but continues at a steady pace normally around 6 9 cm a year. This growth is largely controlled by the production of growth hormone. The Adolescent phase of growth is generally accompanied by a growth spurt, occurring in girls around the age of 11 and boys around the age of 13. This growth is influenced by the body s sex hormones together with growth hormone. The precise timing of puberty and the accompanying growth spurt varies widely from child to child. Children with PWS do not follow this normal pattern of growth, due to the dysfunction of the hypothalamus and reduced levels of hormones. They tend to be shorter and more overweight than other children the same age. They also may not undergo the normal growth spurt associated with puberty.

13 How do you check my child s progress? Growth monitoring Many of the results of growth hormone therapy in your child will be obvious to you. You will see that they are growing faster and similarly to other children their age. You will find you have to buy clothes and shoes more often, as your child outgrows them. Your child s doctor will also monitor your child s growth every 3 to 6 months by measuring height and weight. The doctor will maintain a growth chart tracking their progress and showing the target height. Additionally, a hand x-ray, to check bone age, may be taken every year. The doctor will utilise all of this information to determine how well the therapy is working, and whether or not the dosage needs to be adjusted. Growth charts Growth charts for height and weight are used to track and measure a child s growth from birth to 18 years of age. Separate charts are used for boys and girls, and each has a series of curved lines that plot expected growth in your child s progression to adulthood. Each of these curved lines are called centiles and indicate your child s growth progress in relation to that of other children their age. For example, if your child is growing along the 25th centile, then he/she is larger than 25% and smaller than 75% of the other children of the same sex and age. It is usual for most children to grow and progress along a single centile. Each time your child s height is measured it should be recorded. This creates a picture of how fast your child is growing. While children don t grow at a consistent rate throughout childhood, the centile bands and growth charts reflect this. Special charts may be available from your paediatrician or endocrinologist to record the height and weight of children with PWS. These differ in a number of ways from the standard growth charts you may have been given soon after your child s birth. These unique Prader-Willi Syndrome charts can be useful when your child starts growth hormone treatment. By recording your child s weight and height, in time you will be able to see the impact that treatment is having on growth, stature and body weight and composition.

14 Positive prospects The outlook for children with Prader-Willi Syndrome can be greatly improved through careful management of their diet, a structured exercise programme and hormone treatment. Before long, growth hormone treatment will have become a part of everyday life for your child and family, and the benefits of treatment should soon become evident.

15 Remember: Short stature can be successfully treated with growth hormone Treatment can help to reduce fat and build up muscle Improved body composition can help enhance well-being and quality of life Growth hormone therapy is simple, easy to administer, and will quickly become a part of daily life You are not alone always ask your healthcare team if you have any questions or concerns Genotropin PWS Gen 2929 v3.indd 15 30/4/09 13:28:39

16 Where can I go for more help or information? Your paediatrician or endocrinologist should be able to answer most of your questions on the health and care of your child. If you have any concerns you should bring them to their attention as soon as possible. Sharing experiences with families and carers of other children with PWS can provide valuable support and insights into growing up with this condition. There are many organisations and resources which can put you in contact with other families and provide you with help and information. In addition to the organisations listed below, books, websites, community parenting classes, social and medical services and parent organisations can provide a wealth of information and advice. Your healthcare specialist will also be able to provide you with contact information of local organisations. Prader-Willi Syndrome Association Child Growth Foundation Contact a Family Kidscape Clinic details Provided by Date of production: April 2009 GEN 2929